void AssimpModel::loadModel(std::string path) {
    Assimp::Importer import;
    const aiScene * scene = import.ReadFile(path, aiProcess_Triangulate |  aiProcess_GenSmoothNormals |
        aiProcess_CalcTangentSpace | aiProcess_FlipUVs);
    if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode)
    {
        std::cout << "ERROR::ASSIMP::" << import.GetErrorString() << std::endl;
        return;
    }
    directory = std::filesystem::path(path).parent_path().string();
    processNode(scene->mRootNode, scene, glm::mat4(1.0f));
}

void AssimpModel::processNode(aiNode* node, const aiScene* scene, glm::mat4 parent_transformation)
{
    std::cout << node->mName.C_Str() << std::endl;
    aiMatrix4x4 nodetrans = node->mTransformation;
    nodetrans = nodetrans.Inverse();
    glm::mat4 glmnodetrans = ConvertMatrixToGLMFormat(nodetrans);
    printMat4(parent_transformation);
    glm::mat4 globalTransformation = parent_transformation * glmnodetrans;
    transformarray.push_back(globalTransformation);
    // process all the node's meshes (if any)
    for (unsigned int i = 0; i < node->mNumMeshes; i++)
    {
        aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
        meshes.push_back(processMesh(mesh, scene, globalTransformation));
    }
    // then do the same for each of its children
    for (unsigned int i = 0; i < node->mNumChildren; i++)
    {
        processNode(node->mChildren[i], scene, globalTransformation);
    }
}